Problem: Simplify to lowest terms. $\dfrac{35}{20}$
What is the greatest common factor (GCD) of 35 and 20? $35 = 5\cdot7$ $20 = 2\cdot2\cdot5$ $\mbox{GCD}(35, 20) = 5$ $\dfrac{35}{20} = \dfrac{7 \cdot 5}{ 4\cdot 5}$ $\hphantom{\dfrac{35}{20}} = \dfrac{7}{4} \cdot \dfrac{5}{5}$ $\hphantom{\dfrac{35}{20}} = \dfrac{7}{4} \cdot 1$ $\hphantom{\dfrac{35}{20}} = \dfrac{7}{4}$